It depends what you mean by good lens? Personally, if you're just starting out I would recommend getting a body + lens kit. But it depends what you want. You could get a Canon 600D body ($500) and beginner type 50mm f/1.8 ($125) or better 50mm f/1.4 ($400) or pro 50mm f/1.2 ($1,600) as an example. You could get a Nikon D3200 or Sony A58 each with an 18-55mm kit for $550, with similar pricing in 50mm primes.

There aren't necessarily cameras that are good for portraits. The lens is what matters most for that. Generally portrait focal lengths are from around 85mm-135mm (full frame equivalent) with a maximum aperture of f/2.8 or wider to give you the ability to use shallow depth of field.

Also do you intend to shoot groups of people? In that case you would want something around 50mm (full frame equivalent) or wider. Do you intend to use flash?--Good luck and happy shooting!